Door operator locking mechanism



May 28, 1968 K. DAUGIRDAS ET L- 3,334,994

DOOR OPERATOR LOCKING MECHANISM Filed June 13, 1966 FlGJ INVENTORS KRISTUPAS DAUGIRDAS CARL BY W32 34 FIGB ATTORNEY United States Patent 3,384,994 DOOR OPERATOR LOCKING MECHANISM Kristupas Daugirdas, Wilmette, and Carl W. Roth, Des Plaines, Ill., assignors to Vapor Corporation, Chicago, 111., a corporation of Delaware Filed June 13, 1966, Ser. No. 557,040 3 Claims. (Cl. 49-13) ABSTRACT OF THE DISCLOSURE Locking mechanism for a door operator to lock a door of a public conveyance in closed position including a cam mounted on the output shaft of an operator and coacting with a latch assembly.

This invention relates in general to a door operator locking mechanism, and more particularly to a locking mechanism for locking doors of a public conveyance in closed position.

The locking mechanism of the present invention is applicable to a public conveyance, such as subway cars, street cars and the like which are provided with door operators and over-center linkage arrangements for drivingly connecting the door operator to a door. The locking mechanism includes a cam mounted on the output shaft of a door operator and coacting with a latch assembly that is operable during actuation of the door operator. Moreover, the locking mechanism eliminates the heretofore required secondary locking mechanisms which have been complex and have required much maintenance.

In a public conveyance, it is important to lock the doors in closed positions when the conveyance is moving. A motor driven door operator is normally employed to drive a door between open and closed positions. The locking mechanism of the present invention is adapted for use with a door operator, and includes a notched cam mounted on and rotatable with the output shaft of the operator and coacting with a pivotal latch member that engages in the notch when the door is closed. A solenoid drives the latch to unlatched position, and also actuates a switch that indicates the locking mechanism is in unlocked condition. This switch further functions to deenergize the motor of the door operator at the end of the door closing cycle. A switch is actuated by the cam during the opening cycle to slow down the door operator at the end of the opening cycle, and a switch is actuated by the cam at the end of the opening cycle to deenergize the motor of the door operator.

It is therefore an object of the present invention to provide a new and improved door operator locking mechanism for locking of a door in 'closed position, and especially wherein over-center linkage arrangements are employed and maintained positively in locked condition even against vibration or forces applied at the car door.

Another object of this invention is in the provision of a locking mechanism for a door operator capable of eliminating heretofore employed complicated secondary locking arrangements.

Still another object of this invention resides in the provision of a locking mechanism for a door operator that employs a locking cam and lock latch assembly for actuating switches to control the door operator and to indicate when the operator is in an unlocked condition.

A further object of this invention is to provide. a lock ing mechanism for a door operator employing over-"center linkage between the door and operator, and wherein the over-center linkage is forced toward locked condition it shock loads are applied to the door while in closed position.

A still further object of this invention is to provide a 3,384,994 Patented May 28, 1968 locking mechanism for a door operator that includes means for permitting manual unlocking thereof, and which is simple and compact.

A still further object of this invention is in the provision of a door operator locking mechanism capable of being placed within the confines of a control cabinet in an accessible location thereby allowing easy and efficient maintenance of the locking mechanism.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheet of drawing, wherein like reference numerals refer to like parts, in which:

FIG. 1 is a front elevational view of the door operator having a locking mechanism in accordance with the invention and showing the parts with the door in closed position;

FIG. 2 is a top plan view of the door operator and locking mechanism of FIG. 1, wit-h some parts removed for purposes of clarity; and

FIG. 3 is an enlarged front elevational view of the locking mechanism with the parts shown in position when the door is closed.

Referring now to the drawings, a door operator 10, of the general type shown in the Daugirdas Patent 3,104,- 098, issued Sept. 17, 1963, is illustrated as being mounted on a base 11 that would be mounted within a car in a location for suitable connection to doors for opening and closing of same. It should be appreciated that the door operator 10 may be arranged for opening and closing one or more doors depending on how it is installed within a car. The door operator would include an output shaft 12 having connected thereto an over-center linkage arrangement 13. The over-center linkage arrangement would include a crank 14 carried on the shaft 12 and pivotally connected at opposite ends to connecting links 15 and 16. The free ends of the connecting links would be in turn connected pivotally to a multiplying lever assembly such as that indicated by the numeral 17 for the link 15. A similar multiplying lever assembly would be provided for the link 16, but which is not shown for purposes of simplicity. The multiplying lever assembly includes a lever 18 pivoted at one end to a bracket 19 that is fixed to the frame of the car and at the other end to a bar 20 that is in turn connected to a door 21. A door opening would be provided in the car for the door 21 or the door 21 plus another door section that would be operated by another door operator arrangement. While the embodiment shown is constructed to operate doors for spaced openings in a car, it should be appreciated that it could be employed for operating a single door. The over-center linkage arrangement 13 is arranged so that when the door is in closed position as shown, the pivot connection between the crank and the connecting link 15 is slightly below a horizontal line extending through the center of the output shaft 12, whereby further movement of the door toward open position forces the linkage more over-center, and toward locked condition. Similarly, the over-center locked condition for the link 16 would be when the pivot connection between it and the crank is slightly above a horizontal line extending through the output shaft 12.

The locking mechanism of the present invention includes generally a locking cam 22 and a lock-latch assembly 23 coacting with the cam. The cam 22 is secured and rotatable with the output shaft 12 of the operator, and includes a lobe portion 24 that extends approximately terminating at one end at 25 and at the other end bya notch 26. The lock-latch assembly 23 includes a latch bar '27 pivotally mounted near one end of a pin 23, and

provided with a nose 29 at the other end which coacts 27 is raised by a solenoid 30 having a plunger or armature 31 pivotally connected to the latch bar 27 at a point between its pivot point and nose. A spring 32 is provided to apply a continual biasing force against the latch bar 27 to urge it away from the solenoid 30. It should also be appreciated that upon deenergization of the solenoid 30, gravity will operate to urge the latch bar 30 to a down position or in a clockwise direction about the pin 28. Thus, energization of the solenoid 30 raises the nose 29 of the latch bar 27 out of the cam notch 26 to allow rotation of the output shaft 12 and locking cam 22 in a counterclockwise direction as viewed in FIG. 3 to allow opening of the door.

Raising of the latch bar 27 aetuates a switch 33 for operating a suitable signal to indicate to an operator that the locking mechanism is not in locked position. A limit switch 34 is provided to be operated by the cam 22 at the end of the door opening motion to deenergize the motor of the door operator 10, while the switch 33 also functions to deenergize the motor at the end of the door closing operation. A further switch 35 is employed to insert a resistor in parallel with the motor armature of the door operator to slow the door movement after approximately two-thirds of the door operator opening motion. During the opening operation, the cam 22 holds the locking latch up in a position to maintain the switch 33 actuated while the latch bar rides on the cam lobe 24.

Further, the locking mechanism may be manually operated to unlock the output shaft and permit opening of the door, by pressing down on the end of-the latch bar on the side of the pin 28 opposite from the nose 29 as indicated by the numeral 23a, and then pressing downward on the connecting link 16 to bring the linkage arrangement 13 to over-center position so that it may enable the doors to move to open position.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

1. In a vehicle having a door opening and a door selectively movable between open and closed positions relative to said door opening, a door operator having an output shaft rotatable between first and second positions for opening and closing cycles of said door, means drivingly connecting said output shaft to said door, and a locking mechanism for locking said door in closed position, said locking mechanism comprising, a cam secured on and rotatable with said output shaft and having a notch thereon, a lock latch assembly coacting with said cam to lock said shaft against rotation when the cam and shaft are in the position corresponding to the closed position for the door, said lock latch assembly including a'solenoid and a latch bar operated thereby into and out of locking engagement with the notch on said cam, said latch bar being normally resiliently and gravitationally urged into engagement with said cam when said solenoid is deenergized and moved out of engagement therewith by energization of said solenoid, a switch operated by said cam to deenergize the door operator at the end of the opening cycle, and a switch operated by said latch bar indicating said door in locked position and deenergizing the door operator at the end of the door closing cycle.

2. The combination as defined in claim 1, and a switch engaged by said cam during the opening cycle to cause the door operator to slow down at the end of the opening cycle.

3. The combination as defined in claim 1, wherein said means connecting said output shaft to said door includes an over-center linkage arrangement that is self locking when the door is in closed position, and said lock latch assembly in lock position maintains said linkage arrangement in over-center locked condition.

References Cited UNITED STATES PATENTS 1,914,359 6/1933 Butts 49-280 X 2,637,920 5/ 1953 Stratton 49264 X 3,104,098 9/1963 Daugirdas 4914 3,237,932 3/1966 Catlett 49-30 3,247,615 4/1966 Kalog 49-30 FOREIGN PATENTS 744,697 1/1933 France.

DAVID J. WILLIAMOWSKY, Primary Examiner.

J. KARL BELL, Assistant Examiner. 

